potential energy diagrams

In an exothermic reaction, heat is ...

• Released

• Absorbed

• Synthsized

• Decomposed

The value of ΔH for an exothermic reaction is always...

• Positive

• Either positive or negative

• Negative

• 0

The chemical reaction 2H₂O --> 2H₂ +O₂ shows what process?

• Bond Making

• Bond Breaking

• Bond Forming

• Bond Togetherness

You are in the lab reacting calcium chloride and water. You experience an exothermic reaction as heat is being released from the system. Which potential energy diagram best illustrates this exothermic reaction?

• A

• B

Which of the following is true about endothermic reactions?

• Heat is released

• The reaction feels warm/hot

• Heat is absorbed

You are in the lab and you react ammonium nitrate and water. Your observe that the reaction is cold. Which best describes the type of reaction between ammonium nitrate and water?

• Exothermic Reaction

• Combustion Reaction

• Unidentifiable Reaction

• Endothermic Reaction

Based on the following Energy Diagram, which statement best describes this image?

• The reaction is endothermic because the heat energy of the reactants is less the energy in the products. This means heat is absorbed in the reaction.

• The reaction is endothermic because the heat energy of the reactants is greater the energy in the products. This means heat is released in the reaction.

• The reaction is exothermic because the heat energy of the reactants is less the energy in the products. This means heat is absorbed in the reaction.

• The reaction is exothermic because the heat energy of the reactants is greater the energy in the products. This means heat is released in the reaction.

The potential energy diagram of a reaction is shown. Which statement below is correct relating to this reaction?

• #1 represents the enthalpy change for this exothermic reaction.

• #2 represents the enthalpy change for this endothermic reaction.

• #3 represents the enthalpy change for this endothermic reaction.

• #4 represents the enthalpy change for this exothermic reaction.

During an exothermic reaction, heat content in the surroundings increases because

• heat energy is destroyed during reactions

• the reaction absorbs heat energy

• the energy contained in the reactants is lower then the products

• the energy contained in the products is lower than the reactants

The diagram represents two solids and the temperature of each. What occurs when the two solids are placed in contact with each other?

• Heat energy flows from solid A to solid B. Solid A decreases in temperature

• Heat energy flows from solid A to solid B. Solid A increases in temperature

• Heat energy flows from solid B to solid A. Solid B decreases in temperature.

• Heat energy flows from solid B to solid A. Solid B increases in temperature.